Process of eliminating excess diazo compounds



' sazo `compoundare decomposed by the action Which the'diazo compound and the diaZo-diof the hydrazine compound is due, in part at leastto the solubility of the former and to Vthe relative inso'lubility of vthe" platter. By prolonged treatment with a hydr'azine com pound, all diazopbodies, in general, both soluble and insoluble are ultimatelydecomposed;

In a similar manner,the same'orother diazo vcomponents maybe eliminated .in thev manufacture of other. azo coloring matters.

The process is particularly advantageous inthe elimination of excessdiazo bodies whenV onl'yone' diazo groupor diazotised body fis present,'1`iarticularly at the completion of the j final or last" coupling, Yandiespeciallyv ifgthe presence ofthe Aexcess diazo compound is areaction mixture containing diazobenzene l .and dlazobenzidine.-azo-lfaminonaphthol- -disulfonicacid-aZo-benzene and resulting detrimental to'the isolation of the tinal dye- Vstnina pure or puriiied state. Further,

v the present invention is useful in the pu'riina` tion otmaiiy 'substances Whichrare contaminjatedwith'amino"bodies bydiaZotising the amino body and then `destroyingthesame by means of asuitable'hydrazinebody in acid,V lneutral onalkal'ine'-solution. j

.VmlLzIn thep'roduction-.of an 'azodyestuili the@ improvement YWhich comprises treating Vwith krphenylhydmzinefp-sulfonic acid-f and alkaline: *reaction -mixture containingV di'azobenzene and .diaZo `loenzidinegazo-l.ZS-amanona'phthol-S.ti-.disulfonic acid-azo-ben'zene and resulting Vfrom thecoupling of Idiazobenzi- Y dine-.ano 1.8 V-f aminonaplithol- 3.6 disulfonic acid Withan excess of diazobenzene inan al-4 kalinefmedium, whereby thediazoben'zene is decomposed. l l

a*Zo-l.8faminonaphtholf-S.fi-disulfonicA acidazobenzene, l.the improvement Vwhich l' comL prisestreatingwith a 'soluble aryl hydrazine aminonaphthol-S.-disulfonic acid, with an excess of 'diazobenzene, vwhereby theA diazof benzene isA decomposed, and` coupling the d1- In the, productionkv of m-phenylene'diamf ine s aZobenZidine-azo-l-8-aminonaphthol y( lisulonic acidfraz'ob'enzene, the improvement lwhich vcomprises treating With'a phenylhydraylin'e sulfonic acid an alkalinejreaction mixture containing diazobenzene anddiazoben'zidine azo-LSA aminonaphthol R- 36- disulionic acid-,azo-benzene and resulting from the coupling of `diazobenzidine-aZol.84amino and coupling theV diaZobenVzidine-azo-1.8am inonaphthol-3.6-disulfonic acid-aZobenZene With mphenylenediamine-v t. In the production of m-phenylenediamine-azo-benzidinesazol-aminonaphthol-3-6- disulfonic acid-azobenzene, the improvement which comprises treating Withphe'nylhydrazine-p-sulfonic acid an alkaline reaction mixture containing diazobenzene and diazoben- YZidin'eazoll.S-aminonaphthol3.6disul:tonic acid-azo-benzene and resulting from the coupling of diazobenzidine-aao-lB-aminonaphtliol-S-disulfonic vacidWitli an excess of diazobenzene in an alkaline medium, Where# by the diazobenzene is decomposed, and cou npling the diazobenzidine-'aZo-l.S-aminonaph tliol-3-6-'disulfonic acid-s'izobenz'eney with mL Plienylenediamine. f i' if j i 5'. Iny they product :ionv ofan,V azo coloring matter by combining anV afzo'dye component with diazo compound,fan'd wherein latthe completion of the combination-the resultant reactionVv mixture containsa portion of said l 'diazo compound inthe '.u'ncombined `state,

vthe process whichfcomprises subjecting said` resultant reaction mixture tothe actiono'f av hydrazineV bodyfuntil-4 said unc-ombinedv diazo compound isdecomposed.

" 6j,- Insthe production off an azo'f. coloring matter by'A combining an -azo dye component a diazo compound, and 'Where'inuat the completion of the combination'the resultant reaction mixture f contains a portion of said diazo compoundinthe uncombined state, the process Which lcomprises subjecting ysaid resultant reactionj'mixture to theV actionfof a Ysoluble arylhydra'zine body inthe presence of an alkaline medium untilsaid uncombine'd y n p 'V diazo compound is decomposed. i, Q .'.In the production of .an'azobenzidine- `7.Y In the productiono an azo coloring` matter by combi-ning an afzo dye component with a diazo compoundyandvwherein at the 'completi-on' of the combinationthe resultant reaction mixture'contains 'a-portion of said diazo compound in the1uncombined lstate',the

process Which comprises subjecting said re-V sultant reaction mixture' to theaction offa soluble phenylliydra'zine sulfonic vacid in the presence ofjan 'alkaline medium until rsaid uncor'nbined diazo compound is decomposed. A process which comprisessubjecting a mixture containing a soluble Vdiano compound 'and an insoluble diazold-i'sazo compound Ato the-action of a soluble arylhydrazine sulfonic acid in the presence of'an'alkaline'medium until said soluble diaz-o' compound is substantially decomposed. In testimony whereof I aliix inysignature. ALEON v(SrIflIJLER.

l Traumi@1 eeaisuirenie ma wan an excess of diazobenz'enejin anx'alkaline medium,

uwherebythe dia'zobenzene is decomposed,

CERTIFICATE F CORRECTIN. y

Patent No. 1,815,903. Granted July 28, 1931, to

l LEON W. GELLER.

VIt is hereby certified that error appears in the printed specification of the 'above numbered patent requiring correction `aus follows: Page 2, line 31, claim 1, for "and" read an; line 86, claim 5, before "diazo" insert the article "a"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this lst day of September, A. D. i93l.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

